Nicotine chemical structure

Synthetic organics dominate the field of new insecticides. Much time and money have been spent in attempting to determine the chemical structures of rotenone, pyre-thrum, and other natural insecticides, and to reconstruct them through synthesis. A great deal has been learned about the chemical structures of these compounds, but little success has been attained toward synthesis. Nicotine and, recently, a pyrethrumlike compound are exceptions, but the synthesis of nicotine is too expensive to be practical. The basic information obtained has possibly been helpful in directing the thoughts of the chemist to the synthesis of entirely new compounds. 

We have also noted some strange behaviour with fluorinated pyridines, for example, 3-fluoro nicotinic acid (Structure 6.19 and Spectrum 6.12). The signal for H= (approx. 8.1 ppm) clearly shows couplings of 9.1, 2.9 and 1.7 Hz. The 9.1 Hz coupling must be from the fluorine as it does not appear anywhere else in the spectrum and its chemical shift distinguishes it from either of the other two protons. 

The addictiveness of a given substance goes beyond the chemical structure of the addictive drug itself (i.e., morphine, cocaine, or nicotine). The effects are also related to the dose and speed of delivery, as well as to other substances that might be part of the formulation. For example, just as the oral consumption of opioids and cocaine produce substantially less pronounced behavioral and physiological effects than intravenous or smoked consumption, slow release forms of nicotine produce generally less pronounced effects than smoked forms (Henningfield and Keenan 1993). Similarly, the free base or unprotonated forms of cocaine and... 

In recent years much has been learned about the chemical structure of certain receptors. The nicotinic receptor on skeletal muscle, for example, is known to be composed of five subunits, each a glycoprotein weighing 40,000 to 65,000 daltons. These subunits are arranged as interacting helices that penetrate the cell membrane completely and surround a central pit that is a sodium... 

An alkaloid is a complex organic chemical substance found in plants, which characteristically combines nitrogen with other elements, has a bitter taste, and typically has some toxic, stimulant, analgesic effects. There are many different alkaloids, 30 of which are found in the opium plant. While morphine is the most important alkaloid in opium—for its natural narcotic qualities as well as providing the chemical structure for heroin—another alkaloid, codeine, is also sought after for its medicinal attributes. Other alkaloids include papaverine, narcotine, nicotine, atropine, cocaine, and mescaline. While the concentration of morphine in opium varies depending on where and how the plant is cultivated, it typically ranges from 3 percent to 20 percent. 

The direct-acting cholinomimetic drugs can be divided on the basis of chemical structure into esters of choline (including acetylcholine) and alkaloids (such as muscarine and nicotine). Many of these drugs have effects on both receptors acetylcholine is typical. A few of them are highly selective for the muscarinic or for the nicotinic receptor. However, none of the clinically useful drugs is selective for receptor subtypes in either class. 

Therapeutic Function Ganglion depressant, Smoking deterrent Chemical Name Pyridine, 3-(l-methyl-2-pyrrolidinyl)-, (S)-Common Name Nicotine Nikotin Structural Formula ... 

The acute toxicity (i.e., lethal potency) of imidacloprid, other neonicotinoids, and related analogs in mammals is most closely related to potency at the 7 nicotinic receptor subtype, followed in order by potency at 1x4, fSx, 0(3, and aj nicotinic receptors, respectively. However, acute toxicity in mammals involves complex actions (agonist and antagonist) at multiple receptor subtypes and these actions vary greatly with minor changes in chemical structure. 

Fig. 3.9 Chemical structures of natural products and analogs with nicotinic, muscarinic, cholinergic and dopaminergic activities.

Mechanistically, neuromuscular blockers combine with nicotinic receptors on the postsy-naptic membrane to block competitively acetylcholine (ACh) binding. This prevents conformational changes of, and sodium passage through, the ion channels in the membrane. Once applied to the neuromuscular end-plate, NMBAs desensitize the muscle cells to motor-nerve impulses and ACh. Chemical structures of acetylcholine and representative NMBAs are depicted in Figure 10.1. 

Despite the apparent simplicity of the chemical structure of nicotine, its metabolism is complex and involves a variety of intermediates and enzyme systems (Figure 4). The metabolism of nicotine involves... 

The most important natural sources of minor tobacco alkaloids are from Nicotiana species, and at least eight minor tobacco alkaloids are shown in Figure 1. Since the chemical structures and physical properties of these minor tobacco alkaloids are similar to that of nicotine, some of them are shown to exhibit similar pharmacological activities as those of nicotine, although with a much lower potency. Table 2 shows their relative molar potency in some pharmacological systems. When nornicotine or anabasine was applied to the cat cervical ganglion, initial stimulation was followed by paralysis. On the autonomic ganglion and neuromuscular junction, nornicotine is only one-fifth to one-tenth as active as nicotine. Both nornicotine and anabasine have vaso-depressor action and affect the respiratory system. 

Nicotine (NIK-uh-teen) is a thick, colorless to yellow, oily liquid with a hitter taste that turns brown when exposed to air. It occurs in high concentrations in the leaves of tobacco plants and in lower concentrations in tomatoes, potatoes, eggplants, and green peppers. Nicotine gets its name from the tobacco plant, Nicotiana tabacum, which, in turn, was named in honor of the French diplomat and scholar Jean Nicot (1530-1600), who introduced the use of tobacco to Paris. Nicotine s correct chemical structure was determined in 1843 by the Belgian chemist and physicist Louise Melsens (1814-1886) and the compound was first synthesized by the research team of A. Pictet and A. Rotschy in 1904. 

Chemical Name 2-[[3-(trifluoromethyl)phenyl] amino]-3-pyridinecarboxylic acid Common Name 2-[3-(trifluoromethyl)anilino] nicotinic acid Structural Formula ... 

Figure 6.1 Chemical structures of acetylcholine and nicotinic cholinoceptor ligands used in this study.

Nicotine was isolated by Posselt and Reimann in 1828 [1], and subsequently the chemical structure was clarified [2-4]. As described later, the pyridine ring of nicotine is derived from nicotinic acid, which is biosynthesized from aspartic acid. Therefore, nicotine can also be described as an alkaloid derived from aspartic acid. On the other hand, the pyrroHdine ring is biosynthesized from ornithine.When DL-[5- C]-pyrroline-5-carboxyhc acid, a postulated biosynthetic precursor derived from ornithine, was incorporated into Nicotiana mstica, the incorporated rate (0.04%) was very low, and the 2 - and 5 -positions were equally labeled with (F ure). Consequently, it was estimated that the biosynthetic intermediate was not this compound but another symmetrical structure [5]. 

Although the chemical structure of (-)-anatabine is quite similar to that of (-)-anabasine, remarkably, the biosynthetic pathways of these alkaloids are considerably different. Thus, (-)-anabasine is biosynthesized from nicotinic acid and lysine as described above, whereas, (-)-anatabine is biosynthesized from two molecules of nicotinic acid [2,3], as described in Chapter 10. 

On the other hand, NAD (nicotinamide adenine dinucleotide), known as coenzyme I and II, and NADP (nicotinamide adenine dinucleotide phosphate) are derivatives of nicotinamides. The chemical structures of NAD, NADP, and the reduced form of these alkaloids, NADH and NADPH (nicotinamide adenine dinucleotide phosphate reduced), are shown. Isonicotinic acid hydrazide (INH or isoniazid) is a synthetic derivative of nicotinic acid and has potent antibacterial activity against Mycobacterium tuberculosis (Section 13.2) [1,2]. 

Chemical structure (Figure 8). Nicotinic acid (pyridine-3-carboxylic acid), nicotinamide (pyridine-3-carboxamide), NAD (nicotinamide adenine dinucleotide), NADP (nicotinamide adenine dinucleotide phosphate). 

The most important and toxic of these is coniine, which has a chemical structure similar to nicotine [13, 14, 80]. Coniine is a neurotoxin, which disrupts the workings of the central nervous system and is toxic to humans and all classes of livestock [85]. Ingestion in any quantity can result in respiratory collapse and death. 

They were neutralised with quinine, nicotine, tartaric acid, mandelic acid or (+)-camphor-sulfonic acid. Naturally the optical rotation is changed by the salt formation, but it turns out that the optical rotation of a polymer salt (measured in DMF or methanol) does not depend only on the chemical structure, but also on the tacticity. For example, the optical rotation of the quinine salt of isotactic polystyrenesulfonic acid is considerably more negative than that of the atactic polymer. The tartrates of isotactic poly-2-vinylpyridine are more strongly dextrorotatory than the atactic ones. The optical rotation of the nicotine salts of isotactic and atactic polymethacrylic acid also differs greatly [83]. Finally, mention should be made of complex formation between polymers and chiral shift reagents. Since however the NMR signals and not the CD are investigated in such reactions, they are outside the scope of this report. 

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